net: enetc: allocate vf_state during PF probes

In the Linux kernel, the following vulnerability has been resolved: net: enetc: allocate vf_state during PF probes In the previous implementation, vf_state is allocated memory only when VF is enabled. However, net_device_ops::ndo_set_vf_mac() may be called before VF is enabled to configure the MAC address of VF. If this is the case, enetc_pf_set_vf_mac() will access vf_state, resulting in access to a null pointer. The simplified error log is as follows. root@ls1028ardb:~# ip link set eno0 vf 1 mac 00:0c:e7:66:77:89 [ 173.543315] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004 [ 173.637254] pc : enetc_pf_set_vf_mac+0x3c/0x80 Message from sy [ 173.641973] lr : do_setlink+0x4a8/0xec8 [ 173.732292] Call trace: [ 173.734740] enetc_pf_set_vf_mac+0x3c/0x80 [ 173.738847] __rtnl_newlink+0x530/0x89c [ 173.742692] rtnl_newlink+0x50/0x7c [ 173.746189] rtnetlink_rcv_msg+0x128/0x390 [ 173.750298] netlink_rcv_skb+0x60/0x130 [ 173.754145] rtnetlink_rcv+0x18/0x24 [ 173.757731] netlink_unicast+0x318/0x380 [ 173.761665] netlink_sendmsg+0x17c/0x3c8